Process for clarifying and improving the color of petroleum oils



M. L. CHAPPELL ANI) IVI. IVI. IVIOORE.

PROCES FOR CLARIFYING AND IMPROVING THE CGLOR OF PETROLEUM OILS.

APPLICATION HLED FEB. I8. 1920.

1,404,375.. Patented Jau.24,1922.'

N N @I I I I L u S by O I Nv i a N3 \1\ I Ie N l s n S I N I I N I I i I) Ja N N L S @ma uf 5 I e D m `k :n rl k N t I 2k I j t3\ P' u [7' OCnvI/ENToRs ,m I j Amay/772.77700@ OIL UNITED STATES PATENT OFFICE.

MARVIN L. CHAPPELL AND :MERLEY M.

ASSIG-NORS TO STANDARD OIL COMPANY MOORE, 0F EL SEGUNDO, CALIFORNIA,

0F CALIFORNIA, OF SAN. FRAN- CISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

PROCESS FOR CLARIFYIN G AND IMPROVING- THE COLOR OF PETROLEUM OILS.

Speceation of Letters Patent. Patented Jan.` 24:,- 1922.

Application led February 18, 1920. Serial No. 359,756.

To all whom z'tmay concer-n:

Be it known that we, MARVIN L. CHAPPELL' and MERLE M. MOORE, citizens of the United States, residing at El Segundo, in thecounty of Los Angeles and State of California, have invented-a new and useful Process for Clarifying and Improving the Color of Petroleum Oils, (No. 2,) of which the following is a specification.

This invention relates to the art of clarifying and improving the color of petroleum oils by the use of clarifying and decolorizing agents.' While not necessarily limited thereto, it more specifically refers to ythe art of clarifying and improving the color of lubricating oils.

'One Object of the invention is to provide a method or process whereby a substantially uniform clarified Oil of the desired color may be produced with a minimum consumption of the clarifying and decolorizing agent; another object is to provide such a process which may be performed with a minimum consumption of time.

An object of the invention is to provide a process, for the purpose specified, whereby the oil to be treated andthe clarifying and decolorizing agent may be thoroughly intermingled, in any suitable manner, and not depend upon percolation ofthe oil through the agen p An Object of the invention is to provide a method whereby hydrocarbon oil ma be mixed with a clarifying and decolorizing agent and quickly heated to a temperature of 250 F., or higher, thoroughly commingled and cooled before any substantially oxidizin action can take place.

An object of the invention is to provide a method wherebyy a more finely comminuted decolorizing and clarifying agent may be used to clarify and decolorize a petroleum hydrocarbon Oil than has heretofore been used.

An object of the invention is to prov-ide a method or process whereb the treated oil may be quickly cooled an filtered without loss'in color or the formation of oxidized products. v i

Another object ofthe invention is to provide a means whereby a hydrocarbon. oil containing a small percentage of water, (for instance i of 1% to 2%, approximately,) commingled with a clarifying and decolorizing agent, may be quickly or rapidly heated in such manner as to drive ofi' Or convert all of said water into steam and to exclude substantially all of the air from said hydrocarbon oil, thereby substantially preventing any oxidizing action.

The extraction of coloring matter from petroleum oils is generally understood tO be an adsorbing process, dependent upon time of contact, temperature and surface exposed. For example, for a given quantity and weight the finer the comminution of the decolorizing agent, the more surface thereof will be exposed to the Oily andthe more coloring matter will be condensed or adsorbed \upon the surface of the decolorizing agent. `We have found thatI a decolorizing agent, ground so that approximately 97% will pass through a 200 mesh sieve or screen, gives the more satisfactory results for our process or method. l

Heretofore by usual methods it has been customary to clarify and improve the color of hydrocarbon oils and particularly lubricating oils by percolating such oilthrough long pipes or other forms of containers filled with a decolorizing and clarifying agent, such decolorizing and clarifying agent comminuted Or finely divided so it will pass .through a No. 30 standard mesh sieve but will be retained on a No. 60 mesh standard sieve; also when fullers earth is used for the more viscousoils, the same has been used of such comminution as to pass through a 15 to 3() mesh sieve. In such processes the oil is usually retained at substantially 130 F. These methods have been found very slow and usually require from 5 to 7 days before the Oil percolates through the filtering bed thus formed. lNot only have these methods used been found to be slow but they also require the use of very large quantities of decolorizing agent. With such methods as heretofore practiced it has been noted that the viscosity of the treated oil has been substantially lowered. I

With the usual methods Of clarifying and decolorizing oils it has been customary to subject such oils tojwhat vis known as a brightening operation in which the water is removed from the oil. brightening process air is employed and a percentage of Oxygen is absorbed by the oil with the consequent formation of a percent- Ordinarily in 'thisl age of oxidized products which interfere with the clarifying and decolorizing agent and in the separation thereof from the oil. By our improved process this oxidation is avoided by treating the oil with a suitable decolorizing agent without first employing any such brightening process or removing the water content of the oil after the oil has been treated with acid, caustics or the like.

By our process, in its preferred form, we mix the clarifying agent directly with the oil and do not depend upon mere percolation of the oil through such agent.

llfith our process as hereinafter described and explained we require only approximately 2 hours for the entire treatment of the oil for the purpose of decolorization and clarification and at the same time retain the oil with a greater viscosity than where the usual methods orv processes are used, and also are enabled to perform the clarification and decolorization with a minimum consumption of decolorizing and clarifying agent.

By our process also we obtain a superior product and substantially free from oxidized products.

In the preferred embodiment of our invention our method or process in clarifying or improving the color of hydrocarbon oil consists either in batch treatments or in a continuous method whereby hydrocarbon petroleum or lubricating oil is quickly heated to a temperature between 250 F. and the temperature of the peak of the reaction of a clarifying and decolorizing agent, by means of suitable heating devices, and while such oil is commingled with such clarifying or decolorizing agent, the latter in a finely com minuted or pulverizcd condition, and in such quantities as may be necessary to obtain the desired color or grade; continuing the com mingling or agitating of such oil and decolorizing 'agent for suc a period of time and at such a temperature as is necessary to obtain the desired extraction of color from said oil; continuously discharging the vaporized water in such manner that the vapor substantially excludes the contact of air with the oil undergoing treatment; then immediately partially cooling said oil and said inter-mingled oil and agent to a temperature which substantially prevents oxidation, and then separating from such oil the decolorizing agent and the adsorbed matter by suitable means; and finally cooling the result-ant clarified oil to the desired temperature.

More specially our invention providesA a process whereby a hydrocarbon oil may be intimately commingled with a clarifying and decolorizing agent and quickly brought to the desired temperature forthe reaction of the oil and agent by rapid circulation of the inter-mingling oil and agent through a suitable heater or chamber, without any part of such oil being heated beyond the desired temperature; thoroughly commingling the heated oil and decolorizing agent, discharging the vapor or steam resultant from thel water in the oil and utilizing the vapor or steam thus created toprevent oxidation of the oil; quickly partially cooling the same below oxidizing temperature so as to minimize the oxidation; separating the agent and its adsorbed matter from the oil and then cooling the oil to the desired temperature.

The preferred embodiment of our invention will be more readily understood by reference to the accompanying drawings, illustrating a form of apparatus by which the same may be performed. The drawing is a diagrammatical form of an apparatus by which such preferred embodiment of our invention may be performed.

In the drawings 2 represents a storage tank for the oil to be treated. This tank 2 is connected by a pipe 3 with a treating tank 4. The tank 4 may be entirely open at its top or may be closed by a dome 5 as indicated in the drawings and provided with a vapor outlet 6. The treating tank 4 isy connected by means of a pipe 7 to a pump 8 which discharges through a pipe 9 connected through a valve 10 to a heater 11 and through a valve 12 to a cooler 13. rThe heater 11 may be of any suitable form of construction but we prefer to use a Braun heater which is a heater composed of small pipes enclosed in a shell so that the heating medium fills the shell and surrounds the pipes through which the oil is conducted, thus affording a quick means of raising the temperature of the oil as it passes through the pipes or tubes of the heater. This heater 11 is connected by means of a pipe 14 to the treating tank 4. As shown in the drawings the heater 11 is also connected by a pipe 15 to the pump 8. 16 represents a valve in the pipe or line 15 and 17 represents a valve in the pipe or line 7. 18 represents a storage and feeder bin or hopper in which the nely oomminuted clarifying or decolorizing agent is provided. From this bin 18 such agent may be introduced into the treating tank 4 in the desired quantities, such quantities being regulated by means of a suitable slide or valve 19. 13 represents a cooler which is connected to receiver 21 by a suitable pipe 22. The receiver 21 may be connected to a.

pump 23 by pipe 24. The pump 23 discharges through a pipe 25 which in turn is connected to a filter press, device or chamber 26 of any ordinary or preferred construction. 27 represents a receiving pan to hold the spent clarifying and decolorizing agent. 28 represents a conveyor to convey the spent clarifying and decolorizing agent to storage or for recovery.

The filtering device or press 26 is connected to a cooler 29iby a suitable pipe 30 and in turn the cooler 29 is suitablyconnected to a storage vessel 31 as by a pipe 32. 33 indicates a pipe which leads from the storage vessel 31 to any other suitable placeior `means of storage.

` the pipe 3 from the storage tank 2. This oil may'contain approximately from of 1% to approximately 2% of water. Decolorizing and clarifying agent in the required amount isA then added by suitable operation of the valve 19. This decolorizing agent is thoroughly commingled with the oil by any suitable means, such for-instance, as circulation by means of a pump 8 through the heater 11 and back into the tank 4. This circulation is continued until the commingled decolorizing agent and oil is raised to .a temperature of approximately 250 F., depending upon the oil to be treated. While the commingled oil and agent are thus raised to a temperature between 250 F. and thetemperature of the peak of the reaction of the oil and agent, the Water in the oil is vaporized or turned into steam and as. the oil, agent and steam. or vapor is discharged through the piperll into the tank/4, this vapor vor steam rises and is discharged through the vapor outlet 5 at the top of the chamber 41er through the open top of the chamber if a dome or cover is not used on the chamber. We have found that the conversion of this water into vapor or steam and its rising from the body of oil so being treated with the agent substantially prevents oxidation and substantially excludes ,air from contact with the oil while being thus treated. It is thus seen that this vapor or steam produced by the water in the oil excludes air from coming into contact with the oil while being treated and also excludes or carries the air out of the oil. After the commingled oil and agent have thus been raised to the desired temperature, they are subjected to this temperature for a determined period, which with certain does not exceed 5 minutes. raising the temperature of oil and decolorizing agent the same through a suitable B h 3115 y t us quic y the commingled and circulating heating device,

' we are enabled to subject the commingled oil and .agent to the critical the desired length of time without subjecting any portion of the oil to a greater temperature than desired, thus minimizing the oxidation which would be promoted by too high a temperature and eliminating the dantemperature for Ager of anyportion of the oil approaching decomposing temperature.

prev After thus being subjected to the critical temperature for the desired length of time the commingled oil and agent are immediately passed through a suitable cooler, such as the cooler 13 indicated in the drawings. In this cooler the temperature of the commingled oil and agent'is reduced below the temperature of rapid oxidation and discharged into a suitable receiver 21 from which they are drawn by the pump 23 and discharged through the filtering press or apparatus 26, Where the clarifying agent with the adsorbed coloring matter is separated from the oil and discharged and the clarified and decolorized oil is discharged into the cooler 29 from which cooler such oil may be passed to any suitable storage vessel such as the storage vessel 31.

The passage of the commingled oil and agent through the heater 11 gradually but very quickly heatsl the-commingled oil and agent to the desired temperature Without heating any material quantity of the oil beyond this temperature.

The passage of the treated hydrocarbon oil through 'the cooler 13 rapidly cools said oil to a temperature at which no material oxidation or material lowerin in the color of the `the means of separating the clarifying and decolorizing agent from the oil, our process is not necessarily limited thereto as we may use any suitable filtering means centrifugal machine or other mechanical device by means of which the oil is obtained substantially f ree from the spent clarifying and decolorizing lIAS a clarifying and decolorizing agent, we may use animal char, bone ash, fullers earth, certain clays which have been treated with acid, such as the clays from the well-known Death Valley, California, deposits or any other ordinary or preferred material therefor, and which will clarify and improve the color of hydrocarbon petroleum oil.

In utilizing our process for clarifying and ldecolorizing certain lubricating oils derived 250 F. to the'lieat or temperature at whichV suitable v lclude the contact of air the peak of the reaction takes place. Best results are secured by the higher temperatures so long as the temperature of the comniingled oil' and agent is retained below the temperature of the peak of reaction.

We claim:

1. The process of clarifying and improving the color of hydrocarbon petroleum oil which consists in commingling a hydrocarbon oil containing Water and a clarifying and decolorizing agent, quickly raising the same to the temperature of the decolorizing rc'- action, coincidently discharging the vaporized water to substantially exclude the contact of air With the oil undergoing treatment,

maintaining such temperature to effect such reaction, and then separating the agent and adsorbed coloring matter from the oil.

2. The process of clarif ing and improving the color 0f hydrocar on petroleum oil which consists in quickly raising a commingled hydrocarbon oil containing Water and a clarifying and decolorizing agent to the temperature of the decolorizing reaction, the Water present being volatilized and the resultant vapor utilized to substantially exwith the oil undergoing treatment, maintaining such temperature to effect such reaction, immediately cooling the inter-mingled oil and agent to such a temperature as to prevent rapid oxidation, and then separating the agent and adsorbed coloring matter from the oil.

"3. The process of clarifying and improving the color of a hydrocarbon petroleum oil which consists in commin ling with the oil containing Water a clari ying and decolorizing agent comminuted so that substantially 97% of such agent will pass through a 200 mesh sieve or screen, quickly raising the commingled oil and agent to a tempera- F. and" ture not substantially less than 250 below the peak of the decolorizing reaction, the water present being volatilized and the resultant vapor utilized to substantially ex- 4250" F. and below the temperature! of the' peak of the decolorizing reaction, the Water present being volatilized andthe resultant vapor utilized to substantially exclude thev contact of air with the oil undergoing treatment, maintaining such heat during the period of such reaction, immediately partially cooling the interniingled oil and agent below the temperature of rapid oxidation, and separating the oil and agent with its adsorbed coloring matter.

5. The process of clarifying and improving the color of a hydrocarbon petroleum oil which consists in rapidlycirculating through a heating chamber the oil containing Water and intimately commingled with a. finely comminuted clarifying and decolorizinof agent to cause the reaction of said oil an agent, the Water present being. volatilized and the resultant vapor utilized to substantially exclude the contact of air with the oil undergoing treatment, immediately cooling the same to substantially prevent oxidation, and separating the oil from the agent and adsorbed matter.

Signed at El Segundo, California, this 9th day of Februar 1920.

MAR IN L'. CHAPPELL. MERLE M. MOORE. Witnesses:

G. M. HENDERSON, D. W. FALL. 

